Indications of non-organic hearing loss Inconsistent behavior and performance on tests. Poor test-retest reliability Incompatibility between PTA and SRT Acoustic reflexes found at very loss sensation levels 1 1
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Tests for non-organic hearing loss Objective tests: Acoustic reflex Auditory evoked potentials OAE Behavioral tests: Stenger (Most popular) Lombard 3 3
Stenger test Theory: If two sounds of the same frequency are presented simultaneously to both ears, only the louder tone will be perceived. Used in case of assymetrical hearing loss with at least 25 dB difference between ears. Steps Measure unmasked threshold for both ears separately. Present a 10 dB SL tone in better ear: Response Present a 10 dB below threshold in poorer ear: No response Now, both tones presented simultaneously 4 4
Results of Stenger test Negative Stenger: If response, then, no non-organic hearing loss Positive Stenger: If no response, implies that the tone was heard in poorer ear but patient unwilling to respond. Unaware of tone in better ear because of Stenger effect. Can be done with pure tones and speech. Can also be used to approximate real thresholds by finding the minimum level at which a positive Stenger is obtained. 5 5
Lombard test Theory: In the presence of background noise, individuals speak louder. Ask patient to read or speak aloud. Masking noise is added and gradually increased in level. If patient increases speech level, then masking noise heard. Diagnosis of non-organic hearing loss made based on level of noise and measured thresholds.
Other tests Varying intensity story test: Present parts of story above threshold and parts below threshold, ask questions based on story. Count the number of tones heard Yes/No method (for children)